Fulcrum spar log crane

ABSTRACT

An articulated boom includes a main spar having one end pivotally mounted by a turntable for elevational swinging of an intermediate fulcrum spar having one end pivotally mounted on the swinging end of the main spar and its opposite end forming a log engaging fulcrum, and an auxiliary grab-mounting spar having one end pivoted to the fulcrum spar at a location spaced from its fulcrum end. A grab is pivotally mounted on the grab-mounting spar at a location spaced from the pivot connecting the grabmounting spar and the fulcrum spar. The connected spars are swung relative to each other by fluid pressure jacks. The auxiliary spar is mounted on the upper and outer side of the fulcrum spar so that the three spars can be folded in zigzag relationship.

United States Patent [56] References Cited UNITED STATES PATENTS 9/1967 Larson 72] lnventor Peter J. Cervenak Seattle, Wash.

[21] Appl. No. 41,708

[22] Filed 3,342,357 214/1470 May 27, 1970 [45] Patented Dec'28, 1971 2,831,589 4/l958 214/1476 [73] Assignee Nicholson Manufacturing Company P y Examiner- Robe" Sheridan Seattle, Wash. Assistant ExaminerGeorge F. Abraham Continuation of application Ser. No. y- Robert Beach 600,871, Dec. 12, 1966, now abandoned.

phca'mn May 1970 ABSTRACT: An articulated boom includes a main spar having one end pivotally mounted by a turntable for elevational swinging of an intermediate fulcrum spar having one end pivotally mounted on the swinging end of the main s par and its opposite end forming a log engaging fulcrum, and an auxiliary grab-mounting spar having one end pivoted to the fulcrum spar at a location spaced from its fulcrum end. A grab is pivotally mounted on the grab-mounting spar at a location spaced from the pivot connecting the grab-mounting spar and relative to S8 ..S A WA 1 $0 /64 s 4 .l B T n 7 n "M m n 7 MUMM A m M W m m o m m m Ri m m MN m." m M4 mmm Us mmS Rm LLM m n.Wcm U Zmk F7 UIF M HUN D HUB the fulcrum spar. The connected spars are swung each other by fluid pressure jacks. The auxiliary spar is mounted on the upper and outer side of the fulcrum spar so that the three spars can be folded in zigzag relationship,

PATENTEnnficzmsn @630 398 SHEET 1 OF 2 ATTORNEY FULCRUM SPAR LOG CRANE This application is a continuation of application Ser. No. 600,87l filed Dec. 12, I966 which is now abandoned.

This invention relates to a crane for handling logs and particularly to such a crane intended to handle logs for a specific purpose such as for loading or unloading a vehicle, which vehicle may be a truck or a railway car, or for supplying logs to a processing machine such as a barker or a chipper.

It is a principal object to provide such a log crane which will have a long reach and, at the full extent of its reach, can pick up an unbalanced log with a substantial amount of unbalanced overhang extending beyond the grab and which crane has a boom that can be folded quite compactly in stowed position.

A further object is to provide an effective crane which is strong for its weight, has good mechanical advantage and the parts of which have large relative movement.

In particular, it is an object to provide a crane which can shift a log lengthwise quickly and easily over a substantial distance with little or no change in elevation and which, in any lengthwise shifted position of the log, can shift or swing the log sidewise under complete control without swinging relative to the crane boom.

A further object is to be able to alter the tilt of a log quickly and easily through a considerable angle at will.

Another object is to provide such a crane of simple construction and composed of few parts.

FIG. 1 is a top perspective of the log crane shown mounted on a processing machine, part of which is broken away.

FIG. 2 is a side elevation of the crane with the crane boom in fully extended position, and FIG. 3 is a similar view with the crane boom in a different position.

FIG. 4 is a top perspective of the crane boom with parts broken away.

In the drawings, the log crane has been illustrated in an installation associated with a mobile log-processing machine such as a barker or chipper. Such machine 1 is mounted on a chassis 2 having wheels 3 providing mobility. When the chassis has been stationed at a location adjacent to a stockpile of logs or at some other location where it is to be operated, stabilizing legs 4 can be projected downward such as by hydraulic jacks to assume at least part of the load of the chassis and relieve the load on the wheels 3 to that extent while primarily deterring sidewise tilting of the chassis. Logs are fed lengthwise to the barker or chipper l by a log flight conveyor 5 to which logs can be moved by a roll conveyor ramp 6, the rolls of which may be live rolls, although dead rolls may be satisfactory. Such ramp is swingably connected to the rear portion of the chassis 2 by a hinge 7.

The log crane is mounted on the turntable platform 8 over the log-processing equipment I so that the articulated boom of the crane can be swung from side to side by rotation of the turntable about an upright axis. The articulated crane boom is composed of several spars connected substantially end to end by knuckle joints. One end of the main spar 9 is swingable mounted on the turntable 8 by a pivot 10 for elevational movement about the horizontal axis of such pivot. Such main spar can be swung elevationally by a fluid pressure jack 11 having one end connected to the turntable 8 by a pivot 12 and its other end connected to the main spar 9 by a pivot 13. Such fluid pressure jack is preferably of the hydraulic-type. Extension of such jack will raise the main spar 9 about the axis of its pivot end, while the jack 11 swings relative to both the tumtable 8 and such main spar about the horizontal axes of its pivots l2 and 13.

An intermediate spar 14 is carried by the main spar 9 having one end of such intermediate spar connected by a knuckle joint including the pivot 15 to the swinging end of the main spar. Relative swinging of such spars can be effected by variation in length of the fluid pressure jack 16 having one end connected by pivot 17 to the central portion of the main spar 9 and its other end connected by the pivot 18 to a portion of the intermediate spar 14 adjacent to the pivot 15. The knuckle joint connecting the main spar 9 and the intermediate spar 14 is of the clevis-type, as shown in FIG. 4.

The swinging portion of the intermediate spar 14 in turn carries an auxiliary grab-mounting spar 19. These two spars also are connected together by knuckled joint including a pivot 20. Preferably, this knuckle joint connects one end of the auxiliary spar 19 to a location on the intermediate spar spaced a substantial distance from its swinging end. The auxiliary spar is located to project from the outer and upper side of the intermediate spar which, in other words, is the side of this spar remote from the turntable 8 and mounted end of the main spar 9. The intermediate spar l4 and auxiliary spar 19 can be swung relatively by fluid pressure jacks 21 connected between these spars. One end of each jack is connected to the intermediate spar 14 by a pivot 22, and the other end of said jack is connected to the auxiliary spar 19 by the pivot 23. Both of these jack pivots are located a substantial distance from the pivot 20 connecting these spars.

A log grab is suspended from the swinging end of the auxiliary spar l9 and includes jaws 24 mounted on a body 25 by a common pivot 26. This body in turn is swingably mounted on the swinging end of the grab-mounting spar '19,,preferably by a universal connection including a transverse pivot 27 and a pivot 28, the axis of which is disposed perpendicular to the axis of pivot 27 and disposed in a plane parallel to the length of spar 19. The jaws 24 can be opened and closed by the actuation of the fluid pressure jacks 29 connected between pivots 30 attached to thebody 25 and the pivots 31 attached to the jaws 24. The jacks 29 are interconnected for conjoint operation so that they will both be contracted simultaneously to swing the jaws open relative to the body 25 or closed to clutch a log.

As has been mentioned, the pivotal connection between the intermediate spar 14 and the auxiliary grab-mounting spar 19 is spaced from the swinging end of the intermediate spar. The swinging end of this spar is bifurcated to provide furcations 32 shown best in FIG. 4 to straddle the portion of a log spaced lengthwise from the portion engaged by the grab jaws 24. Fulcrum means span the space between the furcations 32 to bear on the log. Such fulcrum means can be bearing cylinders or rolls 33. The log-engaging sides of these bearing members should at least be rounded to slide easily lengthwise along the log, or such members can be pivoted to roll on the log. Such movement of the bearing members along the log occurs when the log is gripped tightly by the grab and the effective length of the jack 21 is altered to change the angular relationship between the intermediate spar 14 and the auxiliary spar 19, such as between the relationship of these spars shown in FIG. 2 and the relationship shown in FIG. 3.

An important feature of the type of articulated boom utiliaed in the present crane is the long reach of which the crane is capable because the main spar 9 and the auxiliary spar 14 can be moved almost into alignment as shown in FIG. 2. With the main spar and the intermediate spar in these positions, the auxiliary spar 19 suspends the grab beyond the swinging end of the intermediate spar. A log can be picked up by the grab even in an offcenter position, as long as a sufficient portion of the log projects toward the turntable 8 to be engaged by the fulcrum means 33 as shown in FIG. 2. The auxiliary spar 19 can be swung downward about pivot 20 to clutch the log, and, as such grab is raised, the end portion of the log closer to the turntable will be raised into engagement with the fulcrum means 33.

The log L thus engaged can be manipulated in various ways. By shortening further the jack 21, the grab will be raised to swing the portion of the log farther from the turntable 8 upward to level the log or to swing it into an upwardly and forwardly inclined position at almost any angle. If the turntable 8 is rotated, the log can be displaced sidewise in one direction or the other. If all three of the jacks ll, 16, and 21 are operated simultaneously, the spars can be moved conjointly toward folded position such as from the relationship of FIG. 2 to that of FIG. 3. Such relative movement of the spars will shift the log lengthwise toward the turntable with very little change in elevation. Such change in position of the spars can be effected irrespective of the swung position of the turntable 8. If the turntable is swung to align the log with the ramp 6 and conveyor 5, the jack 1! can be contracted while the jacks l6 and 21 are contracted farther so that the log can be laid onto such ramp and conveyor as indicated in broken lines in FIG. 2.

As has been mentioned above, the crane is especially suitable for mobile equipment, so that it is necessary to make the boom structure as compact as possible while the vehicle is traveling. For this purpose, the jacks l6 and 21 can be shortened farther and the jack 1! can be contracted somewhat farther so as to fold the spars 9, l4 and 19 from the zigzag relationship shown in FIG. 3 into the more compactly folded zigzag relationship shown in broken lines in that figure. In this position of the boom the intermediate or fulcrum spar 14 is tucked under the main spar 9 and the auxiliary spar 19 is folded generally alongside the side of the intermediate spar remote from the main spar.

By this stowing operation the maximum extended length of the boom has been reduced approximately 50 percent. Also, the overall height of the crane has been reduced substantially. The height of the assembly can also be reduced by mounting the operator's cab 34 so that it can be swung downwardly from the solid-line position of FIG. 3 to the broken-line position. While the ramp 6 could be stationary, it can, if desired, be constructed to swing upward about hinge 7 into an upwardly inclined position which would facilitate movement of the vehicle from a level to an inclined road, for example. It will be noted in FIG. 3 that the grab can be removed from the auxiliary spar 19 by pulling the pivot pin 27 when the boom is folded to be stowed.

I claim:

1. A log crane comprising an articulated boom including a main spar, an intermediate spar pivotally connected to said main spar and a grab-mounting spar pivotally connected to said intermediate spar, a fulcrum carried by said intermediate spar independent of said grab-mounting spar and engageable with a side of a log to be hoisted, means connecting said main spar and said intermediate spar for effecting relative swinging thereof to engage said fulcrum with such a log, a grab depending from said grab-mounting spar for clutching the log with which said fulcrum is engaged, and means connecting said intermediate spar and said grab-mounting spar for effecting swinging of said grab-mounting spar relative to said intermediate spar and said fulcrum and thereby moving said grab to swing the log relative to said fulcrum engaged with the log.

2. The log crane defined in claim 1, and a turntable pivotally mounting the main spar for upward and downward swinging of its end remote from the turntable.

3. The log crane defined in claim 1, in which the means for effecting swinging of the grab-mounting spar relative to the intermediate spar and the fulcrum includes a jack having one end portion connected to the intermediate spar and its other end portion connected to the grab-mounting spar at a location between the grab and the grab-mounting spar pivotal connection with the intermediate spar.

4. The log crane defined in claim 1, in which the fulcrum is fixed on the intermediate spar.

5. The log crane defined in claim 4, in which the auxiliary grab-mounting spar is pivotally connected to the intermediate spar at a location spaced from the end of the intermediate spar remote from the pivotal connection between the intermediate spar and the main spar and such remote end of the intermediate spar forms the fulcrum.

6. The log crane defined in claim 5, in which the fulcrum includes log-engaging roller means.

7. in a log crane, an articulated boom including a main spar, an intermediate spar shorter than said main spar and pivotally connected to said main spar and a grab-mounting spar shorter than said intermediate spar and pivotally connected to said intermediate spar for disposition of said three spars generally in alignment, means variable in effective length, disposed beneath the adjacent portions of main spar and said intermediate spar and connecting them by bridging across the pivot joinin them, for effecting downward swinging of said intermedia e spar relative to said main spar into a position alongside said main spar by being shortened, and second means variable in effective length, disposed above the adjacent portions of said intermediate spar and said grab-mounting spar when such spars are generally horizontal and connecting them by bridging across the pivot joining them, for effecting swinging of said grab-mounting spar upward relative to said intermediate spar into a position alongside said intermediate spar by being shortened, to dispose said main spar, said intermediate spar and said grab-mounting spar in zigzag folded relationship with said main spar substantially horizontal, with said intermediate spar tucked beneath said, main spar and with said grab-mounting spar folded beneath said intermediate spar when the grab is removed therefrom.

(3)2 3? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,630,398 Dated December 28 1971 Invent Peter J. Cervenak It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 13, cancel "auxiliary"; line 27, after "of" insert --said-.

Signed and sealed this 5th day of September 1972.

(SEAL) Attest:

ROBERT GOTI'ISCHALK Commissioner of Patents EDWARD M.FLETCHER,JR. Attesting Officer 

1. A log crane comprising an articulated boom including a main spar, an intermediate spar pivotally connected to said main spar and a grab-mounting spar pivotally connected to said intermediate spar, a fulcrum carried by said intermediate spar independent of said grab-mounting spar and engageable with a side of a log to be hoisted, means connecting said main spar and said intermediate spar for eFfecting relative swinging thereof to engage said fulcrum with such a log, a grab depending from said grab-mounting spar for clutching the log with which said fulcrum is engaged, and means connecting said intermediate spar and said grabmounting spar for effecting swinging of said grab-mounting spar relative to said intermediate spar and said fulcrum and thereby moving said grab to swing the log relative to said fulcrum engaged with the log.
 2. The log crane defined in claim 1, and a turntable pivotally mounting the main spar for upward and downward swinging of its end remote from the turntable.
 3. The log crane defined in claim 1, in which the means for effecting swinging of the grab-mounting spar relative to the intermediate spar and the fulcrum includes a jack having one end portion connected to the intermediate spar and its other end portion connected to the grab-mounting spar at a location between the grab and the grab-mounting spar pivotal connection with the intermediate spar.
 4. The log crane defined in claim 1, in which the fulcrum is fixed on the intermediate spar.
 5. The log crane defined in claim 4, in which the auxiliary grab-mounting spar is pivotally connected to the intermediate spar at a location spaced from the end of the intermediate spar remote from the pivotal connection between the intermediate spar and the main spar and such remote end of the intermediate spar forms the fulcrum.
 6. The log crane defined in claim 5, in which the fulcrum includes log-engaging roller means.
 7. In a log crane, an articulated boom including a main spar, an intermediate spar shorter than said main spar and pivotally connected to said main spar and a grab-mounting spar shorter than said intermediate spar and pivotally connected to said intermediate spar for disposition of said three spars generally in alignment, means variable in effective length, disposed beneath the adjacent portions of main spar and said intermediate spar and connecting them by bridging across the pivot joining them, for effecting downward swinging of said intermediate spar relative to said main spar into a position alongside said main spar by being shortened, and second means variable in effective length, disposed above the adjacent portions of said intermediate spar and said grab-mounting spar when such spars are generally horizontal and connecting them by bridging across the pivot joining them, for effecting swinging of said grab-mounting spar upward relative to said intermediate spar into a position alongside said intermediate spar by being shortened, to dispose said main spar, said intermediate spar and said grab-mounting spar in zigzag folded relationship with said main spar substantially horizontal, with said intermediate spar tucked beneath said main spar and with said grab-mounting spar folded beneath said intermediate spar when the grab is removed therefrom. 